Congress has completely abdicated its constitutional responsibility to authorize war.

Sipa USA/NewscomAs Donald Trump stumbles through his second year as president, it has become increasingly common to hear warnings about a looming constitutional crisis. Following last week's raid on the office of Trump's personal lawyer, Michael Cohen, which included the seizure of communications with the president, the commander in chief is more agitated than ever, according to various insiderreports.

As Special Counsel Robert Mueller's investigation into links between the president's campaign and Russian influence appears to be reaching its peak, Trump has explicitly acknowledged the possibility that he might fire Mueller. Rumors abound that he is about to fire Deputy Attorney General Rod Rosenstein, who oversees Mueller's investigation.

If Trump were to terminate the jobs of either man, the thinking goes, he would be effectively declaring himself above the law, a man unbound and uninhibited by the most sacred rules of the country he is sworn to govern; a constitutional crisiswould ensue.

These warnings are worth taking into account. There are legitimate reasons to worry about Trump's state of mind, his governing abilities, and the political bedlam that might erupt if he did take action to block the Mueller investigation. But so far these warnings are just warnings, with the potential to spark constitutional breakdowns that, at least for now, remain little more than imagined scenarios, however plausible they may be.

Meanwhile, a real constitutional crisis has been playing out in slow motion, right in front of our eyes, with far less consternation than has been reserved for Trump's still-hypothetical intervention against Mueller.

That crisis comes in the form of Congress' ongoing abdication of its authority to declare war, and to act as a democratic check on the president's ability to use American military might to strike abroad.

Last week, after several days of teasing, Trump announced that American forces had struck multiple targets in Syria. The attacks came in response to reports that the country's president, had slaughtered his own people in a chemical weapons attack. This was the second such attack of Trump's presidency, and the president and White House officials contradicted each other about whether there might be more.

It seems safe to say, however, that the possibility of further strikes remains, even if Trump himself is wary of military intervention; the president's team is more hawkish than ever, and by striking last week after pushing for—and at one point even announcing—a military exit from the region, Trump demonstrated that he can be swayed. The fighting may persist more in punitive bursts than in sustained conflict, but each attack is an act of war. It is an open-ended military conflict, with all that it entails.

Which means that America is, in a very real sense, engaged in a drawn-out, low-level war in Syria. It is a war that Congress has never authorized, which means that it is a plainly unconstitutional exercise of executive power.

Although the president is the commander in chief of the military, the Constitution reserves the power to declare war solely for Congress. The only exception is in the case of an imminent threat against Americans—essentially, self defense.

There is no plausible way to claim that Trump's attack on Syria was an act of self defense; even the most creative acts of constitutional interpretation will not support it. Indeed, Trump himself has declined to make a self-defense argument. Following the strike, the president released a statement insisting that the attack was constitutional as a way to promote U.S. interests in the region while averting "humanitarian catastrophe." This was all but an open admission that the attack did not pass constitutional muster; Trump was citing a justification that the Constitution does not provide.

Trump's Republican defenders in Congress have provided other cover stories for the strike. Prior to the launch, Speaker of the House Paul Ryan cited the authorization for the use of military force (AUMF) passed shortly after 9/11. That authorization, however, provides for attacks on the perpetrators of the September 11th attack and related parties.

Under the past two administrations, that authorization has been stretched practically beyond recognition to essentially grant the president unlimited latitude to unilaterally strike any perceived terror group operating anywhere across the globe. President Barack Obama, after first considering a unilateral attack against Syria and then backtracking to ask Congress for authorization, eventually justified strikes on terror targets inside the country along these dubious lines, with little congressional pushback.

Obama's strikes were poorly justified; Trump's are not justified at all. His latest attack does not fall within the most expansive understanding of the AUMF. Trump's missiles flew against the governing power of a sovereign nation, not a terror cell operating within it. It was an act of war. It was unconstitutional. And Congress allowed it to happen—again.

Although there are a few outposts of principled opposition to unilateral acts of war carried out from the White House—Sen. Tim Kaine (D–Va.) and Rep. Justin Amash (R–Mich.) come to mind—most of the resistance that has come from Congress has been partisan and pro forma, delivered with a collective sigh and an understanding that no real changes will occur.

As Amash recently noted, in 2013, as Obama was mulling an attack on Assad for using chemical weapons, 119 Republicans and 21 Democrats signed a letter urging executive restraint. In 2018, members of Congress drafted a similar to Trump, but the partisan makeup looked rather different, with 15 Republicans and 73 Democrats signing on board.

There is no sustained and organized effort within Congress to return the power to wage war to the legislature. Most of America's elected lawmakers appear willing to let the president exercise that power alone, especially when that president is a member of their own party. They are content to let the Constitution's clear directives go unheeded, and consequently presidents from both parties have been equally content to amass more power to the office. There now exists a tacit agreement between Congress and the executive branch to allow a foundational element of the constitutional separation of powers to slowly degrade. Under Trump, it has all but disappeared.

Those anxiously worrying about an impending constitutional crisis don't need to wait for the rest of Trump's presidency to play out. It arrived years ago, and there are few signs that it will abate soon.

This slow but steady constitutional dissolution may lack the thriller-esque intrigue of Trump's feud with Mueller, or the convenient partisan drama, but it is real enough, and so are the consequences. These illegal acts of war come with body counts, and they risk expanding into larger and deadlier conflicts across the globe.

And they run the risk of exacerbating whatever chaos might ensue should Mueller be forced out. Each new illegal strike helps degrade the rule of law at home, subtly promoting the notion that essential constitutional requirements are mere formalities. Each time a president drops bombs without the authority to do so, it becomes easier for the public to accept the idea that blatant and ongoing violations of the constitutional are somehow a normal part of national affairs. And this, in turn, desensitizes our nation's leaders to such violations, teaching them that constitutional requirements should be criticized on a partisan basis, if at all, and increases the likelihood that when the next constitutional crisis arrives, it too will be greeted with a shrug.